Immunization against many childhood illnesses is now available. Some are standards according to the World Health Organization recommendations, and others are routinely available only in more affluent or developed health care systems. Children in some countries get the full complement of immunizations given in the US. The minimum most children get is some or all of the DPT and Polio series, and the Measles vaccination.
Records should be reviewed for reliability and consistency. Children from some countries come with a predictably reliable record. Others are inconsistent and incomplete. The experienced practitioner can assess whether it is legitimate to consider the immunization record valid and reliable. When in doubt, re-immunization should be done.
Barriers to the documented vaccinations giving adequate immunity are an inconsistent schedule of immunization, a break in the storage safety (i.e., refrigeration), and poor capacity of the child to mount immunity, due to impaired health, and nutritional status. In addition, one should be aware that vaccinations using multidose vials and multiple dose needles without adequate sterilization, carry a risk of actually transmitting diseases, such as HIV and Hepatitis B and C.
Antibody tests can be done to check immunity against most diseases for which immunization is given. Sometimes it's more prudent just to re-immunize without testing, especially when considering the cost of the testing, and that many immunizations can now be given in combination forms, reducing the number of shots. It is generally safe to re-immunize even if the immunity was adequate.
Children who arrive with inadequate documentation should have their titers checked or be re-immunized. Documentation of adequate titers will substitute for a full immunization record for most school systems.
Children without adequate immunity (titers) to the diseases against which they received vaccinations need to be re-immunized.
Checking antibody status in the young child may demonstrate maternal antibodies, not the child's. It is therefore not generally recommended to check the antibodies (titers) on such young children.
A child's medical record may also include naturally acquired infection (measles, chickenpox). Clinicians need to use clinical judgment as to whether to accept these reports.
A complete immunization schedule recommended for children in the US includes: